Connection block



Sept. 7, 1937. H. A. BAKKE Er Al.

CONNECTION BLOCK Filed Jan. 17, .1936

2 Sheets-Sheet l l n l MMM tt Carney.

Inventors: Hans A.Bakke, Har'old F. Crottg.

bg Their' Sept. 7, 1937. H. A. BAKKE ET An.

CONNECTION BLOCK Filed Jan. 17, 1936 2 Sheets-Sheet 2 OW m Inventors;Hans A Bakke, Harold F. Cr-otty,

by Their- Attorney.

Patented Sept. 7,. 1937 .UNITED STATES PATENT OFFICE CONNECTION BLOCKHans A. Bakke, Swampscott, and Harold F. Crotty, Boston, Mass.,assignors to General Electric Company, a corporation of New YorkApplication January 17, 1936, Serial No. 59,580

15 claims. (ci. 1175-183) Our invention relates to connection andterminal blocks for -electrical devices and to connecting links for usein such blocks.

It is an object of our invention to provide a 5 simple, reliable, easilyconstructed, and relatively inexpensive connecting and disconnectingdevice for testing and other purposes in connection with electricalapparatus.

It is another object of our invention to provide 10 a test block for usewith electrical meters, in-

struments, and other devices, which will permit the isolation of theelectrical device from an electrical system without handling thepermanent wiring of the system.

15 It is also an object of our invention to provide a terminal block forelectrical devices which not only permits electrical isolation of thedevice from an electrical system for test purposes but will also permitthe device to be removed readily 20 from its operating position andreplaced therein without the necessity for handling any of the permanentwiring of the electrical system withA which the device is used.

It is still another object of our invention to provide a simplearrangement of connecting links which may be moved in and out ofposition with one hand by an operator and without coming in contact withthe electrical circuit.

Other and further objects and advantages will become apparent as thedescription proceeds.

" In carrying out our invention in its preferred form, we provide aconnection block of insulating material having two parts, eachcontaining elecv trical terminals. The terminals of one part are adaptedfor connection to the internal leads of 3 an electrical device and thecorresponding terminals of the other part are adapted for connection' tothe Wiring of an electrical system with which the electrical device isto be used. 'I'he terminals of one part are hollow and adapted toreceive self-gripping sliding connecting links for making andinterrupting electrical connections between the corresponding terminalsof the parts of the connection block.

Our invention will be understood more readily from the followingdetailed description when considered in connection with the accompanyingdrawings and the features of our invention which are believed to benovel and patentable will be pointed out in the' claims appended hereto.In the drawings, Fig. 1 is a front elevation, partially in section, ofan electric watt-hour meter and connection box containing a connectionblock in accordance with one embodiment of our invention and having aportion of the apparatus removed for the sake of clearness; Fig. 2 is across-sectional view of the portion of theapparatus of Fig. 1 cut bytheyplane 2-2; Fig. 3 is a cross-sectional view of the portion of theapparatus of'Fig. 1 cut by the plane 3; Fig. 4 is an exploded viewillustrating the terminal and connector arrangement of the apparatus ofFigs. 1, 2 and 3; Fig. 5 is `a, front elevation of an enclosedelectrical meter with the cover of the enclosure and a portion of theelectrical meter removed for the sake of clearness and illustratinganother embodiment of our invention; Fig. 6 is a cross-sectional view ofthe portion of the apparatus of Fig. out by the plane' 6 6 when viewedin the direction of the arrow; Figs. 7, 8, and 9 are diagramsrepresenting the circuits of a six-terminal three-wire meter, afour-terminall three-wire meter, and a two-wire meter, respectively;Fig. 10 is a top view of the lower part of the connection block of Fig.1; and Fig. 11 is a rear view of the lower part of the connection blockof Fig. 5.

Referring now more in detail to the drawings in which like referencecharacters are utilized to designate like parts throughout, in Figs. 1to 3, we have shown one embodiment of our invention employed inconnection with an electric meter and connection box of the typedisclosed in the copending application of Isaac F. Kirmard, led January17, 1936, Serial No. 59,598 and assigned to the same aignee as thepresent invention. An electrical watt-hour meter il is shown mountedupon a frame i2 including a terminal connection box i3. The meter ii isof a Well known type having a cup-shaped glass protecting cover it. Thelower portion of the glass cover M has been lbroken away and themechanism of the meter Ill has been removed in order to show moreclearly the connection strips of the meter.

It will be understood that Watt-hour meters are customarily providedwith a potential coil, and one or two current coils, depending uponwhether the meter is to .be used on a two-wire or a three wire electricsystem. These coils are not shown in Fig. 1, but we have illustrated theconducting strips l5-2il utilized for bringing out the connections fromsuch coils. The two ends of one current coil vare connected to one pairof copper strips i6 and i9 by means of screws 2| and, iny a similarmanner, the other current coil is connected to the copper strips I1 andI8. The lighter copper strips i5 and 20 are provided for bringing outthe connections of the potential coil. All of the strips i5 to 20 arecarried in suitable recesses 22 of an insulating plate 23. The recesses22 have shoulders 2l adapted to engage the ends of screws 2i, thuspreventing 'the terminal strips I5 to 20 from dropping out of theirrecesses 22. A gasket 22' of cork or other suitable material may beprovided between the` lower portion 23' of the plate 23 and the portionof the meter base Il' against which the insulator plate portion 23'abuts.

' The connection block, itself, to which our application particularlyrelates is in two parts, 24 and 25,. which are preferably twolindependent pieces for reasons which will be explained hereinafter, butthe parts 23 and 25 need not necessarily be separate and may be integralif desired. Each of the parts 24 and 25 has suitable cavities orchambers 26 and 2l, containing current terminals 28 and 29,respectively, formed from sheets of electrical conducting material. In

, order to close the tops of the cavities 26, the lower portion 23 ofthe insulating plate 23 is arranged to flt into the top portion of theinsulating piece 29 as shown in Fig. 2. We have found that theconstruction of our connection block permits making the meter terminals28 and the line ter-v minals 29 identical, thereby simplifyingmanufacturing operations and reducing the number of diierent partsrequired to be kept in stock by meter manufacturers or power companiesusing electrical meters. The connection block pieces 24 and 25 haveraised or rib portions I0 forming separate pockets for externalconducting members between which dierence in potential may exist.Connectors 30 are provided for connecting corresponding terminals of theparts 24 and 25.

The connectors 39 are composed of resilient electrically-conductingmaterial and comprise long narrow U-shaped links somewhat similar tohairpins in shape. The terminals 28 being holsions are such that theconnectors 30, which are.

sprung apart in a wedge shape, tend to wedge themselves resiliently intothe hollow terminals 28 and thus hold themselves frictionally in anyposition in which they may be left in the terminals Z8. The strips I6,I8, and I9l for bringing out the electrical connections from the currentwindings are also slipped into the terminals 28. In order to secure goodelectrical connections when it is desired to have the electricalcircuits closed, screws 3| are provided which are carried in threadedholes in the meter terminals 28. As seen in Fig. 2, when the link 30 isslid into its lower position, the screw 3| serves to clamp the upper endof the link 3|! against the current lead or strip I6 which, in turn, isclamped against the back of the terminal 28.

In order to insure good electrical contact between the connecting links30 and the line terminals '29, suitable screws 32 having relativelylarge diameter heads 33 are provided. ,'Ihe lower ends 34 of theconnecting links 30 may be spread somewhat in order to form forksfttingaround the shanks of the screws 32, and the heads 33 of these screwsserve to clamp the fork portions 34 against the terminals 29.' Theterminals 29 in the lower part 25 of the connecting block being hollow,they provide openings for receiving the ends 35 of the line conductors36, serving to connect the meter with the electrical system in which theconsumption of energy is to be measured.

Suitable screws 31 cooperating with threaded holes in the terminals 29serve to clamp the ends 35 of supply and load line conductors 36 againstthe back of the terminals :29 and make close electrical contact.

Annular slots 38 may be provided under the removed or when it is beingtested. It will be apparent that the slots 38 prevent test clips 39 frombeing jerked off and either making electrical contacts or forming' arcscausing damage to the apparatus or injury to the operators.

In order to promote the safety and conven ience of those whose duty itis to test or disconnect the meter II, the connecting links 30 arepreferably provided near their forked ends 34 with notches 40 whichpermit sliding the links 30 up and down by means of a screw driver. Itwill be understood that screw drivers with insulated handles are to beemployed and, if this is done, the meter I I can be connected ordisconnected by an operator without touching any live terminals.Furthermore, the arrangement is such that the operator can open andclose the connections with only one hand, thus providing a furtherprecaution against closing an electrical circuit through his body.

When it is desired to open the electrical circuit, the connection links30 are moved one at a time from the lower` position shown in Fig. 2 toan upper position with the forked portion 34 diswith its point insertedin the slot 40. If desired,

the screws 3| may then be tightened to guard against the link 30 beingjarred out of itsupward position inthe terminal 28, although this isgenerally unnecessary as the sides of the resilient terminals 30 becomewedged between the inner surfaces of hollow terminal chambersv28. It isevident that this operation may be performed with one hand since themeter I and the connection box I3 will be attached to the wall or panelon which the apparatus is mounted and need not be held.

The insulated pieces 23p, 24 and 25 may be composed of any suitablemolded insulating compound and, therefore, no diiculty will beexperienced in producing them in the shape shown. It will be seen thatthe screws 3| and 3`| serve to hold the terminals 28 and 29 in thecavities 26 and 21, respectively, and that. the assembly of theconnection block is a relatively simple opera' tion.

When the connection block is composed of the two separate pieces 24 and25, the connection block also provides a means for disconnecting themeter and permitting it to be removed from the connection box I3 andfrom the wall or panel on which it is mounted without any necessity forthe operator to handle the line wires 36 of the electrical system or totouch any live parts. The part 24 is for this purpose fastened in themeter base II by means of screws, not shown, and forms a part of themeter, serving as a terminal block. In fact, if desired, the meter IIwith the terminal block 24 maybe used in the conventional manner inother installa tions as an indoor' unprotected meter. The tips of linewires, similar to that shown at 35, are under such circumstancesinserted in the terminal 28 and fastened by the screw 3l in the mannerillustrated by terminals 29 and the screw 31.

The insulating piece 25, on the other hand, which isadded whenconnecting and disconnecting or testing facilities are desired, isfastened to the back of connection box |3 by screws 39 so that, when thescrews 3| and 31 are loosened and the links 30 are free, being in eithertheir upper or lower positions, the meter |I may be removed from itsposition by removing its supporting screws I2 and moving it upwards, andit will be unnecessary to remove or portions such as a portion 58"slidable in the slots 55 and 56 in the insulating piece 24 or handle anyof the line wires 36. In case the line wires 36 are alive, it will bepreferable, of course, to move the connectors 34 upwards in their upperposition in the terminal block 24 before removing or replacing the meteril in order -that no electrical' circuits will be made or broken whilethe meter is being removed or replaced.

On the three-wire systems of some electric distribution companies, it iscustomary to bring all six leads from the two current coils and thepotential coil of the meter il. to the outside for testing purposes. Forsystems where this practice prevails, we may provide openings 24' (Fig.3) in the insulating piece 24 opposite the potential lead. strips l5 and24. Hollow cylindrical conducting pieces 4i are provided in the upperends of the openings 24 and the potential winding lead strips l5 and 24are bent around to make contact with the pieces 4l, preferably -beingriveted thereto or otherwise fastened.

Figs. 1 and 10).

Transverse openings 42 are also provided in the insulating piece 24 toaccommodate screws 43 carried by the conducting pieces 4I. 'I'heopenings 4|l permit separate insulation covered flexible leads 44 fortest purposes to be inserted and held in contact with the potentialwindings by the screws 43. Suitably bent electrically-conducting strips45 and 46 are carried on the insulated piece 25 and are adapted to makecontact with the two lefthand terminals 29 (see lefthand terminals 29have angular strips 41 and 48 fastened therein (Figs. 2 and 4). Theconducting strip 45 is screwed to'the angular strip 41 (and theconducting strip 46 is screwed to the angular strip 48.. The conductingstrips 45 and 46 are provided with screws 49 for fastening the lowerends of the flexible leads 44 and are provided with winged lugs 50 forreceiving test clips o the jaw type similar to the clip 39.

The electrical circuits of the six-terminal arrangement illustrated inFig. 1 are shown schematically in Fig. 7. It will be seen that circuitsthrough the outer line conductors 36a and 36e are completed through thesliding links 30 and the meter current coils 5I and 52- to the load 53.The potential winding 54 of the meter is connected to the outer pair 36aand 36e of the line conductors 36 on the input or supply side throughthe strips l5 and 26, the flexible leads 44, the conducting strips 45and 46, and the line terminals 25.

If the electric power distributing companies utilizing the meters do notdesire to have sep-` -hand terminal 28 and the strap 56 providing anelectrical connection between the potential lead 25 and the terminal 28adjacent to the lefthand terminal. The electrical circuits arerepresented in Fig. 8. rIhe straps 55 and 56 may be electricallyconnected to the leads i5 and 24 and the terminals 28 in any suitablemanner, vas by means of the screws 5'? engaging threaded openings 59(Fig. 2) in the terminals 2B, and screwsv 58 threaded into the strips l5and 26 (Fig. 5). If desired, the potential connections may be made insuch a manner as to be readily opened, as by making the straps 55 and 55slidable or with For this purpose, two of thel simply by removing thescrews 5l. The screws 5l (Fig. 5) pass through openings5'l' (Fig. 1) inthe piece 24 to engage the threaded openings 59 in the terminals 28. Thescrew 58', however, is threaded only into..an insulating plug, notshown.

In case the meter is used on aL two-wire circuit, it will be understoodthat the current windings 5i and 52 may be connectedl in series or asingle current winding maybe employed, which is connected to the outercurrent leads i6 and i9, the two inner leads il and I8 beingshortcircuited. 54 is connected directly to the current leads i6 and il!and separate potential leads l5 and 24 are not needed. The circuitconnections are shown schematically in Fig. 9.

Our connection blocks are not limited to use in meters of the typeillustrated in Fig, l but may also be employed in any other desired typeof electrical apparatus. In Fig. 5, we have illustrated the use of aconnection block constructed in accordance with our invention but withthe lower piece 25 modified to conform to the spacel available in ameter casing of the type disclosed In this case, the potential windinginUnited States Design Patent 94,322 to Bakke.

It will be observed that, in this case, the piece 25 has its verticaldimension diminished and an' insulating ridge 60 is provided around thepiece 25 to guard against short circuits between thel In the arrangementof Figs. 5 and 6, a modied type of terminal 64 is employed in the lowerinsulated piece 25. This terminal carries a large headed screw 32, as inthe arrangement of Figs. 1 to 4, and has a hollow portion 65 providingan opening for receiving the tip 35 of one of the line conductors 36.The portion 65, however, is at the back of the insulating piece 25' andthe insulating piece 25' has openings extending both upward anddownward, such that line terminal tips 35 may be inserted either frombelow or from r above. In case .they are inserted from above, they maybe passed along the back of the meter il. In installations of the typeillustratedin Figs. 5 and 6, the meters il are ordinarily spacedsomewhat from the back 66 of the enclosing casing 5i.

For the sake of convenience, the arrangement of our connection block forsix-terminal service has been shown in Fig. l and the arrangement forfour-terminal service has been shown in Fig. 5, which also illustrates amodified embodiment of the invention. However, the embodiment of Fig. 1may be employed in four-terminal service by adding the straps 55 and 56of Fig. 5, omitting the flexible leads 44 and omitting or not using thepotential posts 45 and 46. Similarly, the embodiment of Fig, 5 may beemployed in siX-terminalservice by removing or disconnecting the straps55 and 56, and adding exible leads 44 and potential posts 45 and'46. Thebent strips forming the potential posts 45 and 46 of Figs. 5 and 11differ from the corresponding parts 45 and 4'6 of Figs. l and 10 in thatthe strips 45 and 46 pass along the back of the insulating piece 25instead of along the top. In either type of insulating piece, 25 or 25',knock-outs are provided in the portion of. the insulating wall betweenthe terminals 29 or 65 and the ends of the bent strips i5 and 46 or 65and $6 to permit making openings for the screws 61 and 58 or 61 and 68.In the embodiment of Figs. 1 and 10, the strips 45 and 46 are connectedto the angular piece dl and 48 by means of screws 61 and 68,respectively, Whereas, in the embodiment of Figs. and 11, the strips 45'and 46 are connected directly to two of the terminals 29 by means of thescrews 6l and 68', respectively.

In the embodiment of Figs. 5 and 11, the bent strips d5 and t5 may,instead of coming through to the iront of the piece 25', be screwed tointernally threaded metal inserts 69 and 10 in the piece 25' by means ofscrews 'H and 12. The inserts 69 and l0, may, if desired, carryclipholding lugs, such as those shown at 50 in Fig. l. We have hereinshown and particularly described certain embodiments of our inventionandv certain methods of operation embraced therein for the purpose ofexplaining its principle and showing its application but it will beobvious to those skilled in the art that many modifications andvariations are possible and We aim, therefore, to cover all suchmodifications and variations as fall within the scope of our inventionwhich is defined in the appended claims.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. A connection block for an electrical device comprising incombination, insulating means in two parts, each carrying a terminal ofconducting material, and a U-shaped connector of resilient 2. In aconnection block for an electricaldevice, apair of terminals, one ofwhich has an opening facing toward the other, and a connectorresiliently receivable in said opening and slidable in said opening awayfrom and toward the other of said terminals, said latter terminalincluding means for clamping down said connector when slid toward saidlatter terminal, said connector being of such length as to remainpartially Within said opening when engaging said latter terminal.

3. In a connection block for an electrical device, a pair of terminals,o ne of which has an opening facing toward the other, and a connectinglink resiliently receivable in said opening, slidable in said openingaway from and toward the other of said terminals, and having, in aportion protruding from said opening, a transverse slot forreceiving animplement for sliding said link, said latter terminal including meansfor `engaging said connecting link when slid toward said latterterminal, said connecting link being of such length as to remainpartially Within said opening when engaging said llatter terminal.

4. In a connection block for an electrical device, a pair of terminals,one of which has an opening facing toward the other, and an e1on.

gated U-shaped connecting link of resilient electrically conductingmaterial receivable in said opening, resiliently spreading against thesides of said opening, slidable in said opening away from and toward theother of said terminals with the open portion of the U extending towardthe other of said terminals, said latter terminal including means forengaging said connecting link when slid toward said' latter terminal,said connecting link being of such Vlength as to remain partially withinsaid opening when engaging said latter terminal.

5. In a connection block for-an electrical device, a pair of terminals,one of .which has an opening facingtoward the other, and an elongatedU-shaped connecting link of resilient electrically conducting material,resiliently receivable in said opening, tending to spread against thesides of said opening, slidable in said openingY away from and towardthe other of said terminals withl the open end of the U toward the otherof said terminalsv and `having a tool-receiving notch in a portionprotruding from said opening to facilitate sliding the link, said latterterminal including means for engaging said connecting link when slidtoward said 1atterterminal,said connecting link being of such length asto remain partially within said opening when engaging said latterterminal.

6. In a connection block for an electrical device, a pair of terminals,one of which has an opening extending in alignment with and toward anouter surface of the other, and a connector resiliently receivable insaid opening and slidable in said opening away from and toward the otherof said terminals, said latter terminal being positioned so that saidouter surface of said connector is coplanar with said surface of saidlatter terminal, said latter terminal including means for securing saidconnector when slid toward said latter terminal, said connector being ofsuch length as to remain partially within said opening,

when engaging said latter terminal.

7. In a connection block for an electrical device, a pair of terminals,one of which has an opening extending vertically towardthe other,and anelongated U-shaped connector of resilient electrically conductingmaterial receivable in said opening,tending to spread against the sidesthereof, and slidable in said opening away from and tow'ard the other ofsaid terminals, said latter terminal being horizontallyoiset so as tomake its front surface vcoplanar with the back surface of saidconnector, said latter terminal including means for clamping saidconnector when slid toward said latter terminal, said connector being ofsuch length as to remain partially within said opening when engagingsaid latter terminal.

8. In a connection block for an electrical device, a pair of terminals,one of which has an opening facing toward the other, and an elongatedU-shaped connector of resilient electrically conducting materialreceivable in said opening, tending to spread against the sides thereof,and slidable in said opening away from and toward vthe other of saidterminals, the open end of said connector being spread to form a fork,said latter terminal carrying a large headed screw adapted to receivethe forked portion of said connector under its head and to clamp thesame tothe latter terminal when the connector is slid toward said latterterminal, said connector being of such elongated U, the portion of saidstrip at they open end of said U being split further apart acogen than'the remainder of said U in order to provide a portion adapted to engagea clamping screw, the portion of said connector near said clamping screwreceiving portion being transversely slotted to receive the tip of ascrew driver.

l0. A connection block lfor a three-wire fourterminal type watt-hourmeter having two current coils and a potential coil with two leads fromeach of. said coils, said connection block cornprising in combination,an insulating member having two adjacent groups of four chambers each,current terminals in said chambers, slidable current connecting links,and potential connecting straps, the current terminals in one of saidgroups of chambers each being connectible to one of the leads from thecurrent coils and having an opening adaptable to receive one of saidconnecting links in resilient engagement, slidable toward and away froma corresponding current terminal in one of'said second group ofchambers, said links being of such length as to remain in engagementwith the terminals of the nrst group when slid toward and in engagementwith the terminals of the second group, one of said potential strapsbeing connected at one end to one of said potential-coil leads andextending along said insulating member with the other end of said strapover one of said current terminal receiving chambers, theterminaltherein having a screw through said insulating member connectingsaid terminal and said potential strap, the other of 'said potentialstraps being connected at one end to the other of said potential-coilleads-and having its other end over another of said terminal receivingchambers, the terminal in said latter chamber also having a screwthrough said insulating member and connecting the other end of thelatter potential strap to said latter current terminal.

.11. A connection block for a three-wire sixterminal type watt-hourmeter having two current coils and a potential coil `with two leads fromeach of said coils, said connection block comprising in combination, aninsulating member having two adjacent rows of four chambers each,current terminals in each of said chambers, being meter terminals in onerow and line terminals in the other row, slidable currentconnectinglinks, a pair of potential connection strips with potentialposts, and apair of flexible potential connecting links, said current terminalsidentified as meter terminals, each being electrically connected to oneof the current-coil leads and having an opening adapted to receive oneof said connecting links in resilient engagement slidable toward andaway from a corresponding line terminal, said links being of such lengthas to remain in engagement with the current terminals when slid towardand in engagement with the line terminals, one of said potentialconnection strips being electrically connected to one of said lineterminals and the other being electrically connected to another of saidline terminals, said flexible potential connecting links each beingconnectible at one end to one of the potential leads and connectible atthe other end to one of the potential posts.

l2. A separable connection block for an elec trical device havingcurrent-conducting. leads therein, said connection block comprising apair of cooperating insulating pieces, each having a row of chambers,device terminals in each of the chambers of .one piece, line terminalsin each oi the chambers of the other piece, and slidable connectinglinks, each of said device terminals being electrically connected toone'oi? said leads and having an opening adapted to receive one of saidconnecting links in resilient engagement, slidable toward and away froma corresponding line terminal, said links being of such length that, iithe two pieces of said block are together, the links will remain inengagement with the device terminals when slid toward and in engagementwith the line terminals, saidline terminals being connected to thepermanent wiring of an electrical system. l

13. A separable connection block for an electrical device havingcurrent-conducting vleads therein, said connection block comprising apair of -cooperating insulating pieces, each having a row of chambers,terminals in each of the chambers of one of said pieces for connectionto the leads of the electrical device, line terminals in each of thechambers of the other piece for conjnection to' the permanent Wiring ofan electric system, and slidable connecting links, each of the terminalsin one of said pieces having an opening adapted to receive one of saidconnecting links in resilient engagement, slidable toward and away froma corresponding terminal in theother piece, said links being of suchlength that, if the two pieces of said block are together, the linkswill remain in engagement with the terminals supporting them when slidtoward and in engagement with the corresponding terminals in the otherpiece.

14. In combination, an electrical device having a plurality of leads anda test block for said device comprising an insulating upper piece, aplurality of terminals supported therein and each attached to one ofsaid leads, a removable insulating lower piece, a plurality of terminalssupported therein and connectible to the conductors of an electricalcircuit with which said device is to be used, and a plurality ofconnecting links, the terminals of said upper piece having openingstherein toward corresponding terminals of said lower piece, saidconnecting links being resiliently removable in said opening, slidabletherein toward and away from the positions of the terminals of saidlower piece when the two pieces are together, and oi such lengths that,if said two pieces are together, the links will remain in engagementwith the terminals of the lower piece when slid toward and in engagementwith the latter terminals.

l5. In combination with an electric wiring system having permanentwiring, a removable electrical device for use with said system having aconnection block with two parts, and a plurality oi connecting links,one part of said connection block being rigidly .attached to said deviceand including terminals electrically connected to said device, and theother part of said terminal block being independently separable fromsaid device and including terminals connected .to the wiring oi saidelectrical system, the terminal in one part of said terminal blockhaving openings therein adapted to receive said connecting linksresiliently, said connecting links being slidable in and out of saidopening away from and toward the positions occupied by the terminals inthe other block parts when the two parts are together, said links alsobeing of such length that, if said two block parts are together, thelinks remain in engagement with one terminal when slid toward and inengagement with. a corresponding terminal 'of the cooperating blockpart.

HANS A. BAKKE. HAROLD F. GROTTE',

CERTIFICATE OF CORRECTIONL Patent No. 2,092,651. September 7, 1957.

HANS A. BAKE, ET AL It is hereby' certified that error appears in theprinted specification of the above numbered patent requiring correctionas follows: Page 5, first column, line 1T, claim lO, for the word"adaptable" read adapted; that the said` Letters Patent should be readwith this correction therein that the Esame may conform to the record ofthe oase in the Patent Office.

Signed and'sealed this 19th day of O'ctober, A. L'. 1957.

Henry Van Arsdale. (Seal) Acting Commissioner Aof Patents.

